Introduction
Knee hyperextension is also known as genu recurvatum. It occurs when the leg becomes too straight at the knee joint, placing stress on the back of the knee joint and structures of the knee joint.
Anyone can get hyperextension of the knee. However, it is more commonly seen in athletes, specifically those who play sports like soccer, lacrosse, skiing, or football.
It is often caused by a direct hit to the knee or forces generated during rapid deceleration or stop. According to the American Journal of Sports Medicine, compared to men, women athletes have increased joint instability, putting them at greater risk of injury, especially those who participate in high risk sports activites.
At the time of hyperextension, the knee joint bends incorrectly. This often results in pain, swelling, and tissue damage. In serious cases, ligaments such as the ACL (anterior cruciate ligament), PCL (posterior cruciate ligament), or popliteal ligament (the ligament along the back of the knee) may be ruptured or sprained.
Symptoms
- Pain
- Instability of the knee
- Decreased Mobility
- Bruising and Swelling
Pain
After hyperextension, localized pain in the knee joint is expected. The severity of pain can vary from gentle (mild) to severe. It usually increases when ligaments or other structures are torn or damaged. The pain can be described as a pinching pain in the front of the knee joint or a mild ache to a sharp pain in the back of the knee.
Instability Of The Knee
You may notice instability in your knee joint after a hyperextension injury. In addition, many people describe feelings of their leg “giving out” when walking or difficulty standing on one leg.
Decreased Mobility
You may face a problem while straightening or bending your leg after a hyperextension injury. It could be caused due to swelling around the knee.
Bruising And Swelling
You may observe delayed or immediate swelling and bruising of the knee and surrounding areas after an injury. It can be more severe or even mild, and it is your body’s way of responding to the damaged tissue.
Treatment
It is advised to follow the RICE method after the knee hyperextension injury.
Rest
You should stop the activity that caused the injury and seek medical attention. Avoid any contact sports and take a break from any high-impact or high-intensity activities. Anti-inflammatory medications can be helpful in reducing pain and swelling. And gentle range of motion exercises are best at this time.
Ice
Apply ice to the affected knee for 10 minutes two to three times a day. Ice can help manage pain and reduce (bring down) swelling. To prevent skin irritation, always put a piece of towel between the ice and your skin.
Compression
Compression of the knee with the elastic bandage or compression wrap an help reduce pain and manage swelling.
Elevation
Whenever possible, try to elevate your leg above your heart. You can lie on the bed with your leg on a pillow.
Surgery
Even though it is less common, hyperextension of the knee can also cause ligament tear or rupture. ACL (anterior cruciate ligament) rupture is the most common ligament injury of the knee, and it can occur with excessive hyperextension. Popliteal tendon and posterior cruciate ligament (PCL) injuries can also occur with hyperextension and may need surgical repair as well.
Recovery Time
It can take 2 to 4 weeks to recover from a mild to moderate sprain following a knee hyperextension injury. Therefore, it is important to restrict activities during this time that can further put strain on the knee.
A surgical repair of the damaged or injured ligament often leads to a complete recovery and return to work in a high percentage of cases. It is considered to be the best option for ACL (anterior cruciate ligament) injuries, but it can often come with a longer recovery time of 6 months or more.
Physical therapy is essential to rehabilitate the knee and surrounding muscles to a pre-injury state, and it can also help increase strength and reduce recovery time.